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Brainteasers

March 23, 2006

Brainteasers
Interactive Quiz #105:
Think Clearly

Flying instruments is not particularly difficult. It's figuring out what Air Traffic Control expects that fogs the brain. Learning the hidden powers of IFR and VFR clearances launches any pilot on a direct route to success.


INSTRUCTIONS: Answer the questions as best you can, then click on the "Score my quiz answers" button to see your score and read the explanations. If you don't like your score the first time around, you can change some of your answers and resubmit. To get the most out of this quiz, we suggest you keep trying until you get a perfect score.

NOTE: When more than one answer is true, only the most complete, correct answer will be scored as correct. The answers are assumed to apply within the United States unless otherwise noted.


1. The air traffic system is built upon controllers issuing clearances (usually verbally) to pilots who respond and comply. It's a 1950s system in a 21st-century sky. The simple phrase, "Cleared to ..." is the magic key to IFR clearance phraseology; when you hear "Cleared to ..." you're IFR -- if don't hear it, you're not. For example, when a pilot says, "Request IFR to Muzzyville Muni," the Clearance Delivery controller answers, "Sundowner Six Two One Five Zulu, cleared to ... " (ding -- magic!) and then says the name of a place. In an IFR clearance that place is known as the:
a. Destination Airport
b. Filed Fix
c. Clearance Limit
d. Clearance Fix
2. Ever wanted to be an air traffic controller but didn't think you had the voice for it? Well, you're in luck, because through the FAA-approved Be A Controller* program, you too can issue real ATC clearances to real IFR pilots. Imagine yourself on an IFR clearance in level cruise. You hear a Bonanza pilot call Center requesting an IFR clearance from Ailerona Municipal Airport to Ringworm Industrial. She's on the ground and ready to copy. Center hears the call but the callsign is garbled, so the controller asks you (ta-da!) if you heard it. You say, "Yes," and then, with a nervous quiver to your voice, you relay the callsign to Center. The controller, impressed with your voice, asks you to relay an IFR clearance to the Bonanza. Don't panic. This is your moment to shine. The controller will formulate the clearance and read it to you. Write it down on the Burger King wrapper on your lap. Don't fly that clearance, but instead relay it verbatim to the Bonanza. ATC should prefix this relayed clearance with the phrase:
a. "ATC clears ..."
b. "Cleared to ..."
c. "Attention all aircraft ..."
d. "Clearance will be at your own risk, cleared to ..."


3. Pilots flying VFR should know when a VFR clearance is required. In Quiz #94 we discussed Tower clearances applicable to either IFR or VFR traffic. Now, picture yourself airborne and approaching either Class B or Class C airspace. You are already receiving radar service and are within 10 miles of the airspace boundary. The radar approach controller will issue a VFR clearance into the Class C or B airspace by saying, "Ercoupe Six One Zulu, cleared to enter the Charlie (or Bravo) airspace ..." and then issue any vectors, routes, or altitude restrictions. You may not enter Charlie or Bravo airspace, VFR, until hearing the phrase, "Cleared to enter ..."
a. True
b. False
4. Rarely used and almost universally misunderstood by pilots, controllers and quiz writers, the cruise clearance is an IFR clearance that brings flexibility to outback airfields. Imagine you're IFR at 8,000 feet headed to West Wayward (Texas) Airport, late on a clear night. Not a lot of traffic on the frequency when Center says, "Skylane Three Two Five Four Sierra, cruise 8,000, report canceling IFR." It's a slow night. You can see the destination airport by the gas flares at the nearby refinery. That's good, because there's no published instrument approach at this airport inside non-mountainous, Class G airspace. You want to keep your IFR status until on the ground. Given that clearance, "cruise 8,000," when may you descend? (Chose the best answer.)
a. When you report the airport in sight and ATC says, "Cleared visual approach."
b. Without a published approach (SIAP), ATC must issue crossing restrictions and the minimum instrument altitudes as step-downs until you cancel IFR or are cleared for the visual approach.
c. Right now. You're the PIC.
d. Never. Without an instrument approach, you must maintain the assigned cruise altitude (8,000, in this case) until you cancel IFR.
5. Let's stick with cruise clearances for one more question. You're on an IFR flight plan. Approach Control cleared you to "Cruise 8,000." You have a transponder and Mode C altitude encoding, and it's all certified and accurate. ATC's approach radar (ASR) coverage is excellent in this scenario. The controller has another IFR target, a Cessna 172 at 9,000 feet. Both targets are within 40 nm of the ASR antenna. The Cessna pilot wants to descend. Your flight paths, however, conflict so ATC keeps the Cessna 1,000 feet above you. Both airplane's Mode C's are verified accurate. The controller sees your Mode C altitude readout descend from 8,000 to 7,000 feet. Assume a 4,000-foot MSL minimum vectoring altitude (MVA). Assume targets are within three nm of each other. No visual separation in use. When may ATC allow the conflicting Cessna to descend to 8,000 feet?
a. When ATC observes your Mode C reaching 7,000 feet
b. When ATC observes your Mode C leaving 7,000 feet (for lower)
c. When you report leaving 7,000 (for lower)
d. When ATC observes your Mode C leaving 8,000 feet (for lower)
6. Good controllers hate to talk, making them truly boring at parties. Talk takes time, clogs the frequency and slows the flow. One means of cutting the verbal fat is with abbreviated clearances. If you file a long IFR flight plan loaded with airways, navaids, and fixes, there's little reason for Clearance Delivery to read all that to you over the air. You know what you filed and the controller knows, too. So ATC abbreviates the clearance with the phrase, "... as filed." Imagine: You've filed IFR from Blythe, Calif., to Stockton Airport, requesting 16,000 feet. Your route is direct to a VOR and then via several Victor Airways to the Manteca VOR and then direct to the destination airport. Forget SUAs for the moment, and the weather is VFR. No GPS, either; this is old-school IFR. What must ATC include in an abbreviated IFR departure clearance?
a. Assigned and expected altitudes
b. Destination initial approach fix (IAF)
c. First navaid in the route
d. Last navaid before the destination
7. "As filed," means just that -- what you filed IFR. Here's a common flight plan situation: A pilot files IFR many hours before departure. At that time the weather is good. Later, however, the pilot learns of thunderstorms along the filed route and -- through AFSS (Automated Flight Service Station) or DUATS -- amends the flight plan with a slightly new route. Because the entire ATC system is automated, the amendment automatically goes to all ATC positions along the route affected by the change. Because of this automation, there is no need for the IFR pilot to advise Clearance Delivery (or whatever ATC position will issue the IFR clearance) of the amendment when calling for the IFR clearance. It wastes airtime. Because ATC knows about the amendment, and the pilot (of course) knows about it, the controller may still abbreviate the clearance with "... as filed."
a. True
b. False
8. An IFR clearance gets you nicely through complex airspace. IFR status can also delay a flight for many reasons. At non-towered Class G or E airports, ATC might only allow one IFR in or out at a time, which can cause annoying but avoidable delays. If weather permits, the IFR pilot may depart VFR and pick up an IFR clearance down the road. One way to do this is file a VFR/IFR flight plan, meaning the first portion will be VFR and the second bit IFR. This is called a (_____) flight plan and your IFR status should begin (_____). Fill in the blanks.
a. Compound. Automatically over the first IFR fix listed in the flight plan
b. Concurrent. As soon as you enter the clouds.
c. Composite. Prior to the first IFR fix, if you request and are cleared IFR.
d. Canned (or Stereo). Automatically upon cancellation of your VFR portion of the flight plan with AFSS.
9. Fair weather often entices the instrument-rated pilot to depart VFR without a backup IFR flight plan and head cross-country. It's perfectly legit, safe, and fun; VFR folks do it all the time. However, if the weather turns sour, the VFR drivers must turn tail or turn into mountain litter. The IFR pilot often calls Approach Control to request a pop-up, local, IFR clearance for an instrument approach. Controllers are usually obliging: "Radar contact ... cleared to ... fly heading ... maintain ... cleared approach." Once below the goop, the IFR pilot cancels and there's dancing in the streets. Occasionally a controller will tell the pop-up pilot to contact flight service to file a flight plan first, in keeping with that sticky FAR 91.173. Let's say this happens inside Class E airspace. The instrument-rated pilot must remain VFR until (choose the most complete answer):
a. AFSS accepts the flight plan
b. AFSS accepts the flight plan and the pilot returns to Approach frequency
c. AFSS accepts the flight plan and formulates an IFR clearance
d. AFSS accepts the flight plan, the pilot returns to Approach frequency and Approach issues the IFR clearance
10. This last question has nothing to do with clearances. Instead, you'll need to clearly interpret a DUATS NOTAM we found particularly intriguing:
a. High Altitude Bathysphere Launch, three miles northwest (of AMW), moving eastward reaching up to flight level 250 (25,000 feet)
b. It's a military IR thing: High Altitude Ballistic (route) #3, from northwest (of AMW) reaching up to flight level 250 (25,000 feet).
c. An H-class VOR (High Altitude) located three miles northwest (of AMW) has unmonitored radials, Bypass All radials from northwest (approx. 330 degrees) through east (approx. 090 degrees) between Flight Level 180 and Flight Level 250
d. High Altitude Balloon, three miles northwest (of AMW), moving eastward and reaching up to flight level 250 (25,000 feet)


If you enjoyed taking this interactive quiz and would like to see more like it, go to the AVweb Brainteaser page. And if you thought it was unfair, confusing, or a waste of time, we'd like you to tell us that, too. And if you have an idea for a subject that you think would make a good future Brainteaser quiz, be sure to let us know.

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